September was warmer than usual

3.10.2019 15:16

In the coastal areas and the northern part of the country, September was slightly warmer than usual, while in other parts of the country weather was close to the long-term average.

Photo: Pauli Jokinen

Photo: Pauli Jokinen

According to the statistics of the Finnish Meteorological Institute, the average temperature in September ranged from little over 13 degrees on the south-west coast to around 6 degrees in the north of Finnish Lapland. This was already the eleventh consecutive September that was warmer than average. Last time September was colder than average was in 2008, with 1981–2010 as the reference period.

In terms of temperature, the month was divided into two different periods. The first half of the month was clearly warmer than usual while the latter half of the month was colder than usual. However, during the very last days of the month the temperature rose again to figures that were higher than usual. The month's highest temperature, 26.2°C, was recorded in Konnunsuo, Lappeenranta, on 10 September. This was also the second latest hot day ever recorded in Finland. According to observations, the latest hot day, with the temperature of 25.2 degrees, was measured in Tampere and Seinäjoki on 17 September 1947. The month's lowest temperature, -8.1°C, was recorded in Naruska, Salla, on 19 September.

After a dry summer, rainfall brought relief to the west, while in the east the dry period continued

In the eastern parts of the country, September was drier than usual, while in the west it was rainier. The precipitation levels in September varied from approximately 30 millimetres in North Karelia to a little over 100 millimetres on the south-west coast. The month's highest overall amount of precipitation, 153.8 mm, was recorded in Pyynpää, Rauma. The lowest amount of precipitation was measured in Apaja station, Kuhmo, where the amount of monthly rainfall was 25.8 mm. The most precipitation in the span of one day, 33.9 mm, was measured in Hattula, Sulkava, on 15 September.

Thermal autumn began in the whole country by 17 September due to the weather getting significantly colder at mid-month. This means that the average temperature of the day dropped below 10 degrees. The first snow recorded in statistics fell on 29 September in Kevo, Utsjoki. The snow-depth that morning was 2 centimetres.

Further information:

Weather statistics for September

Weather statistics for autumn

Weather statistics from the climate service tel. +358 600 1 0601 (€ 4,01/min + local network charge)
Weather forecasts from the meteorologist on duty 24 h/day tel. +358 600 1 0600 (€ 3,85 /min + local network charge)